/** @file
  Copyright (c) 1999 - 2014, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials are licensed and made available
  under the terms and conditions of the BSD License which accompanies this
  distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php.

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
/*
 * Copyright (c) 1985, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Portions copyright (c) 1999, 2000
 * Intel Corporation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *
 *    This product includes software developed by the University of
 *    California, Berkeley, Intel Corporation, and its contributors.
 *
 * 4. Neither the name of University, Intel Corporation, or their respective
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS, INTEL CORPORATION AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS,
 * INTEL CORPORATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/*
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Portions Copyright (c) 1996 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)res_comp.c  8.1 (Berkeley) 6/4/93";
static char orig_rcsid[] = "From: Id: res_comp.c,v 8.11 1997/05/21 19:31:04 halley Exp $";
static char rcsid[] = "$Id: res_comp.c,v 1.1.1.1 2003/11/19 01:51:35 kyu3 Exp $";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <ctype.h>
#include <resolv.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#define BIND_4_COMPAT

/*
 * Expand compressed domain name 'comp_dn' to full domain name.
 * 'msg' is a pointer to the beginning of the message,
 * 'eomorig' points to the first location after the message,
 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
 * Return size of compressed name or -1 if there was an error.
 */
int
dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
      char *dst, int dstsiz)
{
    int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);

    if (n > 0 && dst[0] == '.')
        dst[0] = '\0';
    return (n);
}

/*
 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 * Return the size of the compressed name or -1.
 * 'length' is the size of the array pointed to by 'comp_dn'.
 */
int
dn_comp(const char *src, u_char *dst, int dstsiz,
    u_char **dnptrs, u_char **lastdnptr)
{
    return (ns_name_compress(src, dst, (size_t)dstsiz,
                 (const u_char **)dnptrs,
                 (const u_char **)lastdnptr));
}

/*
 * Skip over a compressed domain name. Return the size or -1.
 */
int
dn_skipname(const u_char *ptr, const u_char *eom) {
    const u_char *saveptr = ptr;

    if (ns_name_skip(&ptr, eom) == -1)
        return (-1);
    return ((int)(ptr - saveptr));
}

/*
 * Verify that a domain name uses an acceptable character set.
 */

/*
 * Note the conspicuous absence of ctype macros in these definitions.  On
 * non-ASCII hosts, we can't depend on string literals or ctype macros to
 * tell us anything about network-format data.  The rest of the BIND system
 * is not careful about this, but for some reason, we're doing it right here.
 */
#define PERIOD 0x2e
#define hyphenchar(c) ((c) == 0x2d)
#define bslashchar(c) ((c) == 0x5c)
#define periodchar(c) ((c) == PERIOD)
#define asterchar(c) ((c) == 0x2a)
#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
           || ((c) >= 0x61 && (c) <= 0x7a))
#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)

#define borderchar(c) (alphachar(c) || digitchar(c))
#define middlechar(c) (borderchar(c) || hyphenchar(c))
#define domainchar(c) ((c) > 0x20 && (c) < 0x7f)

int
res_hnok(
    const char *dn
    )
{
    int pch = PERIOD, ch = *dn++;

    while (ch != '\0') {
        int nch = *dn++;

        if (periodchar(ch)) {
            (void)NULL;
        } else if (periodchar(pch)) {
            if (!borderchar(ch))
                return (0);
        } else if (periodchar(nch) || nch == '\0') {
            if (!borderchar(ch))
                return (0);
        } else {
            if (!middlechar(ch))
                return (0);
        }
        pch = ch;
        ch = nch;
    }
    return (1);
}

/*
 * hostname-like (A, MX, WKS) owners can have "*" as their first label
 * but must otherwise be as a host name.
 */
int
res_ownok(
    const char *dn
    )
{
    if (asterchar(dn[0])) {
        if (periodchar(dn[1]))
            return (res_hnok(dn+2));
        if (dn[1] == '\0')
            return (1);
    }
    return (res_hnok(dn));
}

/*
 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 * label, but the rest of the name has to look like a host name.
 */
int
res_mailok(
    const char *dn
    )
{
    int ch, escaped = 0;

    /* "." is a valid missing representation */
    if (*dn == '\0')
        return (1);

    /* otherwise <label>.<hostname> */
    while ((ch = *dn++) != '\0') {
        if (!domainchar(ch))
            return (0);
        if (!escaped && periodchar(ch))
            break;
        if (escaped)
            escaped = 0;
        else if (bslashchar(ch))
            escaped = 1;
    }
    if (periodchar(ch))
        return (res_hnok(dn));
    return (0);
}

/*
 * This function is quite liberal, since RFC 1034's character sets are only
 * recommendations.
 */
int
res_dnok(
    const char *dn
    )
{
    int ch;

    while ((ch = *dn++) != '\0')
        if (!domainchar(ch))
            return (0);
    return (1);
}

#ifdef BIND_4_COMPAT
/*
 * This module must export the following externally-visible symbols:
 *    ___putlong
 *    ___putshort
 *    __getlong
 *    __getshort
 * Note that one _ comes from C and the others come from us.
 */
void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
#endif /*BIND_4_COMPAT*/
